A resolution-improvement scheme of a phase-shifted analog-to-digital converter (ADC) is presented and experimentally demonstrated. To improve resolution via the scheme, the optical output of each quantization channel is quantized by an electrical ADC with multiple thresholds instead of a comparator. A 9.9-GHz sinusoidal analog signal is sampled and quantized using the proposed enhancement scheme. The effective number of bits of 4.31 and the spur-free dynamic range of 40.89 dB are obtained, thus indicating an improvement of 0.66 bits and 7.47 dB, respectively.
© 2013 Chinese Optics Letters
Yang Wang, Hongming Zhang, Yujie Dou, and Minyu Yao, "Experimental evaluation of resolution enhancement of a phase-shifted all optical analog-to-digital converter using an electrical analog-to-digital converter array," Chin. Opt. Lett. 11, 082301- (2013)